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  1. KJ6EAD

    circuit board testing ?

    Use your diode test to check from pin 3 to pin 5 on this device: On Semiconductor IGBT Driver MC33153P http://www.onsemi.com/pub/Collateral/MC33153-D.PDF Also check D2, D5, D7, CZ1, CZ2 and CZ3.
  2. KJ6EAD

    Testing resistor

    That's what I was thinking. Besides seeing the trace pattern, this is another reason to show both sides of a PCB when posting. It's so hard to get children, slaves and prisoners in the third world to produce consistently good solder joints. :rolleyes:
  3. KJ6EAD

    Disco lighting upgrade

    What specific lamp type. Does it have an ANSI number? We'll need this to determine the luminosity, dispersion angle and base type. Color is also important as LEDs produce specific colors without wasting energy in filters.
  4. KJ6EAD

    Testing resistor

    Just turn the knob to the 200k scale and measure it. It's a little surprising that the resistor was open. Please post your results.
  5. KJ6EAD

    MAKE: Electronics Ex. 10 Help Needed

    Fry's carries the NTE brand of components so your 2N2222 would be their NTE123A. Do you mean the Ametron in Hollywood, CA?
  6. KJ6EAD

    Testing resistor

    You can test the diodes with your meter and continuity through the fuse and what looks like some kind of thermal switch positioned between a pair of 2k resistors acting as heaters. Another possibility to check is that the switch is making good contact since this is partially dependent on the...
  7. KJ6EAD

    Helping hands with magnifier

    I have this $7 one from Harbor Freight. The magnifier is too weak so I got a more powerful lens. It has 2 white LEDs but they're near the back of the lens housing pointed the wrong direction so I'm building a full ring of LEDs into the lens housing along with an adjustable current source...
  8. KJ6EAD

    Boost antenna range

    Being an IT guy, I guess the antenna you're using is made for WiFi (2.4GHz) so it's electrical length is quite a bit shorter than what's optimal for the FM broadcast band, but as long as you're aware that the antenna itself can attenuate your signal, carry on.
  9. KJ6EAD

    MAKE: Electronics Ex. 10 Help Needed

    A 2N6028 is a unijunction transistor. It's not an appropriate substitute for a 2N2222. Did you get that at Radio Shack? They have a reputation for such errors.
  10. KJ6EAD

    MAKE: Electronics Ex. 10 Help Needed

    Neatness counts when you're trying to make something understandable to others. It also goes a long way in making troubleshooting easier. I don't fold my socks but I've sometimes numbered the pairs to keep the wear even in cases where I had several identical pairs. :p
  11. KJ6EAD

    Hijacker needs help (LED traffic lights)

    http://www.google.com/url?sa=t&source=web&cd=7&ved=0CFEQFjAG&url=http%3A%2F%2Fwww.ti.com%2Fgeneral%2Fdocs%2Flit%2Fgetliterature.tsp%3FgenericPartNumber%3Dcd4017b%26fileType%3Dpdf%26track%3Dno&ei=jWWZT8GmGsHK2AX9s4iADA&usg=AFQjCNEWcq4W3sLsrQd8Ce5z1ht-1Tc3bA The 4017 can source 25mA at 12V. The...
  12. KJ6EAD

    MAKE: Electronics Ex. 10 Help Needed

    I had to fight with the editor but now the photos are up there.
  13. KJ6EAD

    Boost antenna range

    The RF output of the BH1417F is pin 11. On the Belkin Tunecast and Tunecast II transmitters, there is a T or pi attenuator network and a small base load inductor. The antenna is a short length of wire alongside the input pigtail. These things were done to make the output so weak that adjacent...
  14. KJ6EAD

    What are these pieces?

    They're some kind of connector pin, the female side. The thin end gets a wire soldered into it after the pin is inserted into a connector body.
  15. KJ6EAD

    MAKE: Electronics Ex. 10 Help Needed

    For what it's worth, I built the circuit using a 2N3904 transistor and a yellow high brightness LED and powered it with 12V. With the switch closed and the LED lit the following values were measured: emitter 10V, 12mA; base 10.8V, 150μA; collector 10.2V, 12mA; LED 2V, 12mA. All voltages...
  16. KJ6EAD

    Guitar Pedal Project!

    It doesn't. That's just a rating from a label.
  17. KJ6EAD

    Guitar Pedal Project!

    Does your effect pedal have a coaxial DC power jack? If so, what labeling does it have? If the connector is right, I'd use an MPD BK-030 battery box with NiMH rechargeable batteries. That should get you at least four times the run time...
  18. KJ6EAD

    circuit board testing ?

    That was frustrating. Lot's of almost clear enough pictures. The key to good pictures is lots of indirect light, no flash and the correct lens and distance.
  19. KJ6EAD

    Wiring Police Light Bar

    That documentation seems good. You need a 12VDC power supply capable of up to 15A. You can use an inline fuse holder with an 8A fuse for testing purposes. You may need 10A and 15A fuses for some features. After you have everything tested and identified, install a fuse block and switches as you...
  20. KJ6EAD

    circuit board testing ?

    So far we've tested most of the likely suspects and found nothing out of the ordinary, certainly nothing that would be able to immediately trip an 8A breaker. There are several power diodes on the board that are worth testing. I can't see them well enough to tell you where they are or their...
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